Viruses Flashcards
What does CMV classically cause in BMT and AIDS patients?
BMT patients- CMV pneumonia
AIDS patients- CMV retinitis
Both- may develop CMV colitis, viremia
What two causes of viral gastroenteritis have indistinguishable symptoms? What are they?
Caliciviridae and Rotavirus
Both cause diarrhea, vomiting, and fever
What does coxsackie virus A cause?
Hand, foot and mouth disease
Herpangina
What does coxsackie virus B cause?
Pleurodynia (sharp, u/l pleuritic pain)
Myocarditis, pericarditis
What antibodies would indicate a new vs. and old Hepatitis A infection?
anti-HAV IgM= Acute infection
anti-HAV IgG= Chronic infection
What are the naked DNA viruses?
Papova, Adeno, Parvo, Papilloma (PAPP)
What virus is associated with progressive pulmonary edema and respiratory failure after inhalation of infected rodent droppings?
Hantavirus
Think- 4 corners area (NM, UT, CO, AZ)
What virus is most commonly associated with gastroenteritis on cruise ships and in nursing homes?
Norovirus- diarrhea and vomiting
What is the clinical difference between chicken pox and smallpox lesions?
Chickenpox lesions- Appear in waves, are at different stages, (pustules, scabs, etc)
Smallpox lesions- Develop at the same time, lesions are all the same stage
What is molluscum contagiosum? What virus causes them?
A wart-looking lesion with a dimple in the center, caused by Poxvirus
What is the classic presentation of Chikungunya?
Initial rash, fever, and joint pain following a mosquito bite-> may progress to arthritis that persists
What disease causes a fever and “slapped-cheek” rash in kids? What is the organism?
5th disease, aka Erythema infectiosum
Caused by parvovirus
What enzymes would be elevated in hepatitis vs bile duct obstruction?
Hepatitis- Elevated AST, ALT
Bile duct obstruction (gall stone)- Alkaline phosphates and bilirubin are elevated more then AST, ALT
What is the leading cause of chronic Hepatitis in the US, and the leading indication for a liver transplant?
Hepatitis C
What is the primary cause of pneumonia in young children, with multinucleated giant cell formation?
RSV
What are the 4 segmented viruses?
BOAR- All RNA Bunyavirus Orthomyxovirus Arenavirus Reovirus
Where do RNA viruses replicate? What is the exception?
In the cytoplasm
EXEPT orthomyxovirus and retrovirus replicate in the nucleus
All DNA viruses are double stranded and positive sense except what?
Parvoviridae is single stranded and - sense
DNA viruses have icosahedral symmetry except what?
Poxvirus- Has a box-like complex
What RNA virus is double stranded?
Reoviridae- (Rotovirus)
Where do DNA viruses replicate? What is the exception?
In the nucleus, except Poxviridae replicates in the cytoplasm
What are the characteristics of H5N1 pneumonia?
Primary viral pneumanitis without secondary bacterial infeciton, rapid progression to ARDS or pulmonary edema
What test can be used to diagnose H5N1?
RT-PCR from pharyngeal/nasal washings, immunofluorescence, and will be found in feces
What virulence factor is present in Paramyxovirus that is not present in Orthomyxovirus and causes multinucleated giant cell formation?
Fusion (F) protein
What is the marker that indicates Hepatitis B has high infectivity?
HBeAg= High infectivity
anti-HBeAg=low infectivity
What immunoglobulins will be seen with acute and chronic/resolving hepatitis B?
Acute= IgM anti-HBcAg Old= IgG anti-HBcAg
The presence of what antibody indicates a live hepatitis B infection?
HBsAg (Hepatitis B surface antigen)
anti-HBsAg indicates immunity
What is HDV superinfection?
Infection of HDV in a patient with chronic HBV. Cannot make Anti-HBsAg antibodies. Complications-> fulminant hepatitis, cirrhosis
What are the 2 most common opportunistic infections in AIDS patients with a CD4 count
CMV with retinitis ad Mycobacterium avium (disseminated)
How would classic shingles present?
Painful, burning, rash over one sensory dermatome
What is the difference between CMV and EBV mononucleosis?
EBV will have a positive Monospot test from heterophile antibody.
What virus is responsible for Molluscum contagiosum?
Poxviridae
What virus causes Progressive Multifocal Leukoencephalopathy in the immunocompromised?
JC Polyomavirus
What TORCHeS infection is the most common viral cause of mental retardation?
CMV- Also causes deafness, seizures, microcephaly
How is parvovirus different from the rest of the DNA viruses? What does it cause?
It is ssDNA and negative sense.
Causes Erythema infectiosum (5th dz) and transient aplastic anemia crisis
What mosquito-borne Alpha virus typically does not cause encephalitis?
Chikungunya
What happens when you give a child aspirin when they have influenza or varicella?
Reye’s Syndrome- severe liver/brain disease
What gene products does a Western Blot look for to confirm HIV? What is a positive test?
p24 (major capsid protein), gp41 and gp120 (surface glycoproteins). + test= bands for 2
What genes does an ELISA to test for HIV look for?
gag, pol, and env
For what Hepatitis virus is serology NOT useful?
HDV- fleetingly present
Negri bodies in the brain are consistent with what disease?
Rabies- Rhabdovirus
What clinical manifestations are characteristic of H5N1?
Develop clinical pneumonia with patchy infiltrates-> can rapidly progress to ARDS
How is RSV different from the rest of the paramyxoviruses?
Lacks hemagglutinin and neurominidase
What malignancies are classically associated with AIDS? What are the associated viruses?
B-cell lymphoma (EBV), Kaposi’s sarcoma (HHV-8)
What strains of HPV cause most cervical cancers? What strains cause genital warts?
16 and 18- cervical cancer
6 and 11- genital warts
What fetal defects are most commonly caused by Rubella?
Heart (patent ductus), Eye (cataracts, chorioretinitis), and CNS defects (deafness, microcephaly)
What flavivirus is characterized as being extremely painful?
Dengue fever- Severe backache, HA, and muscle and joint pain
What viruses are in the picornavirus family?
PERCH- Polio, Echo, Rhino, Coxsackie A and B, HAV
What polio vaccine has potential dangerous side effects? Why?
Oral polio vaccine with attenuated poliovirus. It can pick up virulence and cause paralysis in the person taking the vaccine or those exposed to shedding. (Vaccine-associated paralytic poliomyelitis)
